Underwater, there's a spot where sharks are 41 times more abundant than in the open ocean. What attracts them? (video)

The ocean covers a vast portion of the Earth's surface and is home to an incredible variety of species, including some of the most ferocious predators — sharks. The ocean is immense, so it would be logical to assume that sharks are scattered throughout its various corners; however, new research indicates that this is not entirely the case. Researchers have found that the underwater mountains near Ascension Island are literally teeming with sharks — there are 41 times more than in the open ocean, according to IFLScience.

Researchers believe that this trend may suggest that underwater mountains serve as important "centers" where animals gather for communication, mating, and resting. In their study, a team from the University of Exeter focused on examining three underwater mountains near Ascension Island in the southern Atlantic Ocean.

It is noteworthy that two of the three mountains were shallow, with less than 100 meters of water separating their peaks from the ocean surface. The results indicate that these two mountains were habitats for major predators, including Galapagos and silky sharks, as well as yellowfin and bigeye tuna.

The choice of underwater mountains for "gatherings" appeared to depend on the individual characteristics of the animals: some were residents of a specific underwater mountain, while others visited both mountains, which are located about 80 kilometers apart. However, the most intriguing aspect was that the boom in marine life turned out to be quite complex.

Scientists expected to see the highest biomass in the lower levels of the food chain, decreasing slightly with each subsequent level. However, the reality is that the enrichment of marine life increased with each level. Zooplankton was still more abundant on the underwater mountains compared to the open ocean, with the study recording twice as much, but the biomass of sharks was 41 times higher.

According to co-author of the study, Dr. Sam Weber from the Ecology and Conservation Center at the University of Exeter, the results of their work with colleagues indicate that several factors come together to make underwater mountains so rich in marine life, particularly predators.

Although primary productivity is not higher on the underwater mountains studied by the researchers, filter feeders may benefit from the fact that prey is "funneled" through the peak, while the peak may prevent prey species from retreating to deeper waters to avoid predators. This concept effectively concentrates food in one predictable location in the ocean.

Scientists also believe that some predators likely use underwater mountains as "centers" for gathering, socializing, mating, and resting. Predators also utilize underwater mountains as a base to which they return after hunting in the open ocean. The team suggests that this explains why there are more apex predators on underwater mountains than would be expected based on the amount of available food.

The results of the new study also support the widely held theory that underwater mountains are oases of life in the relatively barren deserts of the open ocean. Scientists also believe that these findings highlight the importance of conserving shallow underwater mountains.